| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | be [v-ing] [prep] | 71140 |
|
| 2 | [vb past] be [v-ing] | 7136 |
|
| 3 | [vb past] be [prep] | 4611 |
|
| 4 | [vb past] [v-ing] [prep] | 4392 |
|
